1. Field of the Invention
The present invention relates to a container for producing and dispensing foam.
2. Description of the Related Art
Aerosol bottles for spraying a liquid or a foam by spraying by means of propellent gas are known. In the case of these aerosol bottles, a foam mixture of the foamable liquid and liquefied propellant gas is dispensed through an aerosol valve, the propellant gas expanding after leaving the valve causes the foaming of the liquid. For reasons of environmental protection, there is a need to refrain from the use of environmentally harmful propellant gases. Therefore, bottles in which the propellent pressure is produced by means of plunger type air pumps which are integrated in the bottles have already been developed. The spraying of liquid from such bottles can be performed with conventional aerosol valves. On the other hand, dispensing foam from such bottles is extremely problematical, since in the case of such bottles with air pumps, or in the case of compressed-air bottles, the air acting as propellent gas is not liquefied and consequently does not vaporize (expand) upon leaving the aerosol valve to cause the foaming of the liquid.
Devices of the type for producing and dispensing foam for squeeze bottles are known from Applicants own U.S. Pat. No. 5,048,750, which is not admitted as being prior art, except as required under 35 USC 102. In an axial opening of a securing part intended to be arranged on the neck of the bottle there is provided a mixer part, which has a mixing chamber arrangement into which air and liquid passages open out. The air forced in upon squeezing the bottle and the liquid are intermixed in the mixing chamber arrangement, creating an unrefined foam. In a screen-like refining element, the unrefined foam is refined and conveyed through a channel arrangement to an outlet. Apart from the axial opening, the securing part has openings for secondary air, which is sucked in from the surroundings when the compressed bottle reverts to its original shape. The channel arrangement conveying the foam from the mixer part to the outlet is arranged in a cap which covers the securing part and in which a further channel arrangement for the secondary air is provided. The cap is rotatably mounted between an open position and a closed position in a nut-like manner on a thread of the securing part. In the closed position, a tubular valve body arranged on the cap engages in a valve seat which is on the securing part and formed at the end of a tube intended for conveying the foam, in order to prevent the escape of foam. By turning the cap into the open position, the valve body frees an annular gap-like passage between itself and the valve seat, in order to allow the foam to flow out upon subsequent compressing of the bottle. On the cap there is provided a further closure body, in order to prevent the entry of secondary air into the bottle in the closed position. In the case of this known device, to produce and dispense foam the cap is first turned from the closed position into the open position when the bottle is not pressurized and then the foam is produced and dispensed by compressing the bottle or by pumping air into the bottle. In this process, the forming of the foam is ended by no further compressing of the bottle, or by no further pumping in of air. If after dispensing one or more times no more foam is required, the cap can be turned back to the closed position in order to close the channel arrangement and the opening for secondary air. The known device is not intended, and not suitable, for containers which are put under pressure by means of pumping prior to the removal of foam or are constantly under pressure.